1. Field of the Invention
The present invention relates to a faceting apparatus for cutting gemstones, and more particularly to an interchangeable faceting apparatus which comprises a dual indexing means consisting of a primary indexing gear with a relatively small number of notches and an auxiliary indexing gear which controls the primary gear to provide subdivided indexes, and a height adjusting means for placing a faceter frame in parallel with the lap surface at any selected height of the faceter frame.
2. Description of the Prior Art
There is known to the art a faceting head structure of the type disclosed herein, which comprises index plates having 60-, 64-, 80-, and 96-notch gear wheels commonly used for faceting gemstones. According to the prior art, the trigger should be engaged accurately into each notch. However, this operation usually requires too much time and attention from the operator, and it is therefore said that the number of the notches should be smaller in order to complete the operation both in less time and with less attention. Practically, however, the indexing plates with such small number of notches reduce the number of faceting angles, in other words, faceting a gemstone is incomplete with additional facets of the gemstone left untreated. Therefore, the above conventional indexing plates cannot satisfy practical needs.
The faceting head assembly known to the art includes a height adjusting device which adjusts the height of the faceting frame with respect to the lap surface. The height adjusting device has a foot link hinged to the underside of the frame, or is of a stand-rod type in which the frame is height-adjustably mounted on one side there-of to a stand rod and is fastened thereto by means of a screw at any selected height of the frame. The operation or manipulation of the device requires a high level of experience or expertise as well as much time and attention, particularly when it requires a fine adjustment.